* Focus on Fantasy and Animal Characters: The story primarily focuses on the adventures of Mrs. Frisby, a field mouse, and her interactions with the intelligent rats of NIMH. This makes it more of a fantasy story than a science fiction one.
* Human-Like Intelligence: While the rats exhibit advanced intelligence and technology, this is presented as a result of their own research and development, not as a result of alien contact or advanced technology from the future.
* Realistic World: The story takes place in a recognizable, realistic world, albeit one inhabited by talking animals. The technology and scientific advancements within the story are mostly based on real-world science and concepts.
However, there are elements that lean towards science fiction:
* Super-Intelligence in Animals: The rats' extraordinary intelligence and ability to manipulate technology fall into the realm of speculative fiction.
* Advanced Technology: The rats' inventions, like the electric car and the artificial light, are futuristic for a story set in the real world.
* Exploration of Scientific Themes: The novel touches upon themes of scientific research, experimentation, and the ethics of manipulating nature.
Overall:
* Mrs. Frisby and the Rats of NIMH is best categorized as fantasy with science fiction elements. It uses a realistic setting and animal characters to explore themes of intelligence, technology, and the potential consequences of scientific advancement.